Yes, this number grows gradually more slowly over time, very similar to gold that’s being mined: Initially, it’s very easy to find gold, so there’s plenty coming in. Eventually, it becomes more and more difficult to mine for gold.
The difference between Bitcoin and gold from that perspective is that with Bitcoins, the number of Bitcoins coming into the system is totally predictable. Unlike gold where someone finding a huge new mine (this is very theoretical 
) might make people assume the value decreases, which will actually make the value decrease.
Theoretically yes, practically no: You have more Bitcoins - but you also have more people interested in Bitcoins, so this more or less balances itself out. Eventually, less new Bitcoins enter the system - but there’s also less new people interested in using Bitcoins. It’s kind of a bootstrapping phase of about 30 years until the payment method has been fully established. For the last few years the value has been gradually increasing - except for one bubble phase where the value of Bitcoins rose from just a few cents per Bitcoin to about $30 per Bitcoin (within several months) and then first fell back to $10, eventually decreased to and stayed at around $4 for a while and then started rising gradually again.
Volatility is certainly one of the current risks with Bitcoin: When you suddenly have a lot of people primarily focussed on speculation and making a quick buck coming into the system, the value increases too quickly until some people become scared, jump off and you have a bump.
People actually using Bitcoin as a payment method balance that out. In other words: The more people using Bitcoin for what it’s meant to be used, the more stable the value of Bitcoin becomes.
At the moment, “mining” actually does create new Bitcoins. Over time this becomes less and less as the total number of Bitcoins gets closer to its final number (there can only be a certain amount of Bitcoins which I believe is reached after about 30 years). Eventually, you can add a transaction fee to make your transactions be handled with priority. So, when no Bitcoins can be mined anymore, you basically have a crowdsourced transaction network with transaction fees automatically distributed to those offering that service.
So instead of giving a transaction fee to a single entity (like a bank or PayPal … which … is a bank), your transaction fee is distributed to everyone offering their computing power to validate your transaction.
Kind of … except for it’s usually more than six computers. But six computers is the minimum amount of validation necessary.
I’d say that even after several years, it’s still a pretty new technology and I believe the primary issue keeping growth a little slow is exactly what you’re pointing out: It’s still too difficult to get into it for many people. So there’s the early adopters which eventually pave the way for the rest of the world
And things are changing: For instance, the client is much more convenient and understandable to use compared to two years ago. And there’s a lot more resources to learn about Bitcoin than two years ago. Like always with technology: There’s benefits and risks of getting into a specific technology in its earlier phases.
Maybe a better introduction than checking out the FAQ is this little video: http://www.weusecoins.com
